If you love your coffee and tea but are trying to cut back your caffeine intake, it can be tricky to work out how much you can have without over-stimulating yourself.
While there are some groups who are usually advised to go easy on caffeine – such as pregnant women and people with insomnia, anxiety, irritable bowel syndrome or heart issues – most of us have a green light from health authorities to have a bit of caffeine to fuel us through the day.
In fact, Professor Clare Collins, director of research in the University of NSW’s School of Health Sciences, said that studies have confirmed coffee and tea are generally good for our health.
“The good news is that for now, with the exception of people with health problems, we don’t have to feel guilty about coffee unless we get so over-stimulated we don’t sleep,” she says.
“Even then, we can manage that by the time or the type of coffee or switching to decaffeinated.”
It’s suggested we limit ourselves to 400mg of caffeine per day or 300mg during pregnancy, but working out how many cups of coffee or tea that means is confusing given how much variation there is in each cup.
According to Food Standards Australia and New Zealand (FSANZ), a 250ml cup of percolated coffee has anywhere between 60 and 120mg, an instant coffee has 60 and 80mg, while tea has 10 to 50mg.
“There is natural variability in the plant, between seasons and even within each batch,” Professor Collins says.
“There is also massive variability in the type of tea or coffee you are drinking and how you, or your barista, makes it.”
Caffeine in coffee
Coffee, particularly that made with ground beans in a café, is generally going to be one of your higher sources of caffeine so you’re generally advised to cap your intake at two to three per day.
If that sounds ridiculously low, it might be worth having a decaf or two throughout the day as well, because it’s been found to still have excellent health benefits.
“There are many other bioactives [aside from caffeine] that won’t over-stimulate you,” Professor Collins says.
“The polyphenols kayweol and cafestrol are anti-inflammatory and seem to improve the body’s ability to fight cancer in the early stage, while cholorgenic acid and caffeic acids are phytonutrients that seem to improve the sensitivity of the glucose and insulin response, which means that coffee drinkers are better at clearing glucose from their blood.”
So when it comes to working out the right amount of coffee for you, Professor Collins suggests keeping tabs on your sleep quality and adjusting your intake accordingly.
“The message for coffee and health is that caffeine free or regular coffee is great,” she says.
“In terms of the stimulatory effect of caffeine, it’s about managing your own sensitivity. For some people it’s about managing the time of day you drink it and the type and for other people it’s better to switch to decaffeinated.”
Caffeine in tea
Tea has significantly less caffeine than coffee (a brewed cup of black tea has half the amount of a brewed cup of coffee, and a brewed cup of green tea has a quarter) so many coffee drinkers find it a good alternative if they’re trying to cut back on coffee but don’t want to skip the caffeine altogether.
But given a single cup can have anywhere from 10 to 50mg it’s clear there is a wide variation.
A spokesperson from Lipton said that black tea has the most caffeine, followed by green tea, white tea, then decaffeinated black and green tea. If you want absolutely no caffeine, go herbal — these “teas” are made from botanicals (for example, chamomile, lemon and ginger, peppermint) and do not contain caffeine.
According to the Tea Leaf Journal, different tea leaves on each individual plant also vary in caffeine.
The tea plant buds and new leaves have more caffeine than older leaves on lower parts of the stem, while leaves that are harvested early in spring have more caffeine than those harvested late.
Professor Collins says using a smaller dose of fresh leaves – such as one spoon for a teapot instead of the traditional “one spoon for each person and one for the pot” rule – will likely reduce the amount of caffeine.
But the length of time you steep a teabag does not seem to have a significant effect on the cup’s caffeine content.
“We did a caffeine [test] for a bag steeped for one minute and five minutes and found no difference,” Professor Elizabeth Douglas, senior research fellow at Monash University’s Department of Epidemiology and Preventative Medicine, said.
While some online hacks report that if you steep your teabag for 30 to 60 seconds, discard the water, then add fresh water to the used teabag, Professor Douglas says she’s dubious that it would have a significant effect.
If caffeine in tea is a concern, Professor Collins suggests using decaf varieties because you will still get some of the healthy polyphenols without the added alertness, or researching different tea companies for one that is lower in caffeine.
For example, Hari Har Chai tea, which is grown in the Daintree, uses tea leaves naturally low in caffeine.
And, good news: like decaffeinated coffee, decaffeinated tea still retains much of the health benefits.
“Decaffeinated black tea still retains over half of the natural flavonoid content of regular black tea so you can enjoy the taste of your favourite tea while minimising caffeine intake,” says Lipton’s spokesperson.